WP query for two post types how to order newest to oldest with two different meta fields?

Question

I am doing a simple WP query that gets posts: ('post', 'event').

the events I needed ordered by a custom date field: start_date'

the posts I need ordered by date.

I need the two output together in order.

I read: Query two post types and order by two different date fields

The guys sounds like he did some work with js. I need this to be a paginate-able query. There are 100+ posts and probably 12-14 events.

TIA